Disable moving to Sentbox for now

fix https://github.com/deltachat/deltachat-core-rust/issues/2176

we can re-enable it when DC determines automatically which folders to watch and
this is deployed for at least 1 release.

src/config.rs

@@ -63,6 +63,9 @@ pub enum Config {
     #[strum(props(default = "1"))]
     MvboxMove,
 
+    #[strum(props(default = "0"))]
+    SentboxMove, // If `MvboxMove` is true, this config is ignored. Currently only used in tests.
+
     #[strum(props(default = "0"))] // also change ShowEmails.default() on changes
     ShowEmails,
 

src/message.rs

@@ -119,6 +119,7 @@ impl MsgId {
                 && !msg.is_setupmessage()
                 && msg.to_id != DC_CONTACT_ID_SELF // Leave self-chat-messages in the inbox, not sure about this
                 && context.is_inbox(folder).await
+                && context.get_config_bool(SentboxMove).await
                 && context.get_config(ConfiguredSentboxFolder).await.is_some()
         {
             Ok(Some(ConfiguredSentboxFolder))